“The result is an Earth-like world dominated by lava”

planetary systems form and evolve.

Yet where we find order in the cosmos, there is often chaos. The compositions of the planets that make up the TOI-178 system don’t display the harmony exhibited by their motion. Next to a dense terrestrial Earth-like world is a ‘puffed-out’ low-density planet, followed by an exoplanet with a density similar to that of Neptune.